Transmission chock



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Patented Nov. 2.9, 1927.

NATHANIEL w. aAPHAEL, oF so'orn ORANGE, NEWJEBBEY.

TRANSMISSION CHOCK.

Application iiied April 2s,

This invention relates to mechanism for controlling the action of a transmission mechanismy or geark set such as is used in connection with an automobile engine.

In driving an automobile, it .has been l found that the automobile when at a standstill on an incline moves backward, as the brakes are released preparatory to the letting-in of the clutch and the operation of the 10 gear shift lever to again start the car in motion.

It is therefore one of the objects of the present invention to prevent any accidental backward movement of an automobile, and

Another object of the invention is te combine with the transmission mechanism of an automobile power system, a checking -mechanism with which the drive Shaft ot' the transmission mechanism may be optionally permitted to rotate iii one direction only, or with which the drive shaft Vmay be permitted to rotate in both directions, so that intentional backward movement may be had whenever it .is desired, for instance for intentionally backing the automobile.

Another object of the invention is to pro- VideY an extremely simple and reliable chocking mechanism which will operate in response to movements of the usual sliding gear shift rods of a power transmission mechanism.

With the foregoing, other objects of the invention will appear from the embodiment of the invention which by way of example is described in the following specification and illustrated in the accompanying drawings, in which- Figure 1 is a sectionalelevation of a power transmission' mechanism embodying the present invention. v

Fig. 2 is a sectional View taken onfthe line 2--2 oi.v Fig. 1.

Fi 3 is a detail sectional view taken on the line 3-3 of Fig. 1.

The resent invention is intended for, use in conjunction with a power transmission mechanism such as is included in the power system of an automobile.

In the illustrated embodiment there is shown a power transmission oi' gear set 10 of well known construction and which in cludes an engine shaft 11, a drive s haft 12 to which power is transmitted by virtue of the intervention of a set of @ears 13, lshifting rods 14 and 15 which are lidably mounted 1926. serial No. 105,281.

and opxerate in conjunction with the usual gear s. ift lever 16 and connected parts for obtaining the proper rotational speed of the drive shaft and its reverse rotation.

Employed in conjunction with the powertransmission 10, briefly outlined hereinbefore, is .the chocking mechanism 17 of the present invention, and this mechanism operates in response to movements of the shifting rods 14 for optionally permitting the drive shaft 12 to rotate in one direction only and thereby 4prevent rotation of the shatt which would result in the automobile moving backward, or permitting said shaft to. rotate in both directions so that the necessary and intentional backward movement as well as forward movement of the automobile may be brought about. By arranging the said mechanism 17 so as to operate in conjunction with the shifting rods, an extremely simple and reliable mechanism may be obtained. It is to beunderstood that lthis mechanism maybe diversely formulated, but in the present instance includes a ratchet wheel 18 which is secured to the drive shaft 12 and a pawl 19 which coacts with the teeth of the ratchet wheel 18. The pawl 19 is pivotally mounted as at 20, and the said pawl has an extension or cam engaged ortion 21. The pawl normally coacts with t e teeth lof the ratchet and this may be brought about in different. ways such as by having the portion of the pawl at the ratchet side of the pivot heavier than that portion of the pawl at the opposite side, or as in the present instance there may be employed a spring 22 having one end fixedly attached to a part of the gear case as at 23 and its opposite end connected with the pawl 19 at the ratchet wheel side of the pivot. lIt will now be apparent that the spring serves to normally and constantly urge the pawl in a coacting relationship with respect to the ratchet wheel 18. Arranged on the shift rod 14 are cams 24 and 25, and arran ed on the shift rod 15 is a cam 26. When ie gear shiftin lever 16 `is manipulated to obtain high spee the cam 25 will be moved into engagement with the extension 21 and as a result the pawl 19 will be moved 'against the action of the spring 22 to an inactive position, whereas when the leverl is manipulated to obtain intermediate or second speed the .cam 24 will be moved intoenga ement with the extension 21 causing a simi ar movement of the pawl 19, and when the lever 16 is manipulated for reversing a similar movement of the pawl 1.9 vvill result. These facts are mentionedto make it clear that each time the lever 16 is manipulated for obtaining either high, and second speeds and reverse rotation of the drive shaft, the pawl 19 Will be out of engagement with the ratchet Wheel. When the lever 16 is in a neutral position the pawl 19 willbe in an active position so as to coact With-the teeth' of the ratchet Wheel 1d, due to the'iact that the spring 22 will' auton matically operate to accomplish this. it follovvs therefore that accidental backward movement of the automobile Will be prevented since the drive shaft .will be prevented from rotating except in a direction for any great length of time.

l claim:

1. r1he combination with a transmission mechanism including a drive shaft and shifting rods; of chocking mechanism operable in response to the movement of said shitting rods iior optionally permitting the drive shaft to rotate in one direction only or permitting said shaft to rotate in both direc tions.

2. rlihe combination with a transmission mechanism including a drive shaft and shitting rods; of chocking mechanism operable in response to the movement of said shifting rods for optionally permitting the drive shaft to rotate in one direction only or permitting said shaft'to rotate in both directions, said checking mechanism including coasting means associated with the shifting rods and the drive shaft:

3. The combination with a transmission mechanism including a drive shaft and Leanser shifting rods; of checking mechanism operable in res,y onse to themovement of said shifting ro s for optionally permitting the drive shaft to rotate in one direction only or permitting said shaft to rotate in both directions, said choclring mechanism including.

kpermitting said shaft to rotate in both directions, said chocking mechanism comprising pivotallyl mounted means, means on the shifting rods which coacts with the pivotally mounted means, an4 element on the drive shaft with which said pivotally mounted means is engageahle and disengageable, and means' acting on the pivotally mounted means to releasably hold said .pivotally mounted means in engagement With said element. i

5. The combination with a transmission mechanism including a drive shaft and shifting rods; of checking mechanism operable in response to the movement of said shifting rods for optionally permitting the drive shaft to rotate in one drection only or permitting said shaft to rotate in both directions, said checking mechanism comprising a ratchet Wheel secured to the drive shaft, a pawl Which'coacts with the ratchetwheel, said pawl having an extension, cams secured respectively to the shifting rods Which coact Withsaid extension for moving the pawlto an inactiveposition, 'and means which has a normal tendency to cause the pawl to coact with said ratchet Wheel.

N'ATHANIEL W. RAPHAEL. 

